DESCRIPTION: (Candidate's Abstract) The ultimate aim of this proposal is to formulate a multifaceted program which will guide my development as an independent scientist. This goal is to be accomplished through a mixture of basic research and educational activities. My research will be focused on determining the biologic function of the neurotrophins brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in the development and maintenance of the mammalian eye. These endeavors will be complemented by extramural workshops, instruction in ocular pathology, and participation at scientific meetings. I have spent the past several years completing my doctoral research and professional training. I am now prepared to embark on a long-term career in academic neuro-ophthalmology, combining clinical practice with basic research. The University of Colorado will provide me with an ideal environment in which to accomplish my immediate and long-term goals. The combined faculties and resources of the Department of Neurology, Ophthalmology, and Molecular, Cellular, and Developmental Biology are particularly well suited for providing me with training in nervous system and eye development, mouse genetics, histochemistry, and transgenic and embryonic stem cell technology. Under the research mentorship of Dr. Kevin Jones, I will investigate the biologic roles of BDNF and NT-3 in the neuroretina and anterior segment of the eye. A multidisciplinary approach will address questions in three main areas. First, the cell specific expression of BDNF and NT-3 and their respective receptors. TrkB and TrkC, will be examined in the neuroretina, lens, ciliary body, and cornea. We will identify the specific cells expressing BDNF, NT-3, TrkB, and TrkC using dual-label immunohistochemistry and confocal microscopy. These results will suggest possible functions for these neurotrophins in the eye. Second, the biologic functions of BDNF and NT-3 in the neuroretina will be investigated using subregion-restricted gene knockout technology. Mice will be generated which lack BDNF and NT-3 in the neuroretina. To achieve this, we will use Cre/loxP-mediated recombination restricted by either the Six3 or Brn-3b promoter. Cre recombinase will be expressed either as a transgene or as a dicistronic message using an intervening ribosome entry sequence (IRES). Third, the biologic role of BDNF and NT-3 in the anterior segment of the eye will be characterized following our recent finding of regulated neurotrophin expression in the ciliary body epithelium, lens epithelium, and cornea. Restricted gene knockouts will be constructed using dicistronic Cre expression driven from the endogenous aquaporin-1 gene. These studies should provide novel insight into the molecular genetics of eye development, potentially broaden our understanding of degenerative eye disorders and open new avenues for their treatment with growth factors.